COLLAGEN CORP./ZIMMER PREPARING SHIPMENTS OF COLLAGRAFT BONE GRAFT MATRIX

COLLAGEN CORP./ZIMMER PREPARING SHIPMENTS OF COLLAGRAFT BONE GRAFT MATRIX following FDA approval of the jointly developed product on May 28. Bristol-Myers Squibb subsidiary Zimmer, which is responsible for marketing the product in the U.S., says that it is beginning to take orders for Collagraft. Collagen Corp., which will ship the device, says that it expects to have a large volume of the product available within four to eight weeks. Collagraft will be priced at $625 for 5 cc and $325 for 2.5 cc. The firms project that first-year sales for the product will be modest -- between $7 mil. and $10 mil. Collagen will receive about one-third of the revenues. Initial marketing will focus on the U.S. Zimmer also has Asian marketing rights to the implant, and Collagen has rights for Europe, but neither firm has immediate plans for overseas markets. Collagraft will be sold in a ready-to-mix kit that includes equal amounts of purified fibrillar collagen and hydroxyapatite/tricalcium phosphate ceramic, a spatula and a bowl. Collagen assembles the kits after being supplied with the ceramic component by Zimmer. The bone graft matrix, which in the operating room is mixed with autologous bone marrow, provides "a scaffolding around which the patient's new bone will grow, gradually replacing the graft as the site heals," the firms explain in a June 1 release. Collagen and Zimmer say that Collagraft's surgery success rate is "equivalent to that of autograft[s]," the current gold standard. However, because Collagraft "eliminates the need for a second surgery required to harvest autografts," it "should reduce the costs associated with additional anesthesia and operating room time," the firms claim. In addition, patients treated with Collagraft implants during studies had "less than half the rate" of infection of autograft patients (4.9% vs. 12.4%). The firms say the implant also is an improvement over allografts (human bone obtained from a bone bank); with allografts "fusion rates are variable, healing can be delayed and there is a potential" for viral disease transmission. Collagraft's labeling is in line with recommendations made by FDA's orthopedic and rehabilitation devices panel when it reviewed the product in August 1991 ("The Gray Sheet" Aug. 26, 1991, p. 3). As the panel suggested, the implant is "indicated for use in acute long bone fractures and traumatic osseous defects." The panel expressed concerns about "the safety of collagen products in relation to autoimmune disease" and patients' potential hypersensitivity to the bovine collagen contained in the device. The labeling includes warnings regarding these two issues. Collagraft was deemed approvable by FDA in September 1991. Final approval, however, was delayed pending validation of Zimmer's manufacturing plant. Following validation of the plant, FDA issued an approvable letter in January 1993, Collagen says. Collagen and Zimmer also are working on a second-generation pre-mixed version of the bone matrix graft. The firms hope to submit a premarket approval application supplement to FDA and gain marketing clearance of the device within a year. The second-generation product will be lyophilized into "chewing gum"-like strips. Unlike the first-generation Collagraft, the device will not require refrigeration. In addition, it is designed to be handled more easily and to remain on the fracture better.